Poly(2,2,4,4-tetramethyl-1,3-cyclobutylene carbonate) is a useful polymer for making molded articles. However, the art does not disclose an efficient method for the preparation of high molecular weight poly(2,2,4,4-tetratmethyl-1,3-cyclobutylene carbonate).
Defensive Publication T858,012 discloses a melt method of preparing poly(2,2,4,4-tetramethyl-1,3cyclobutylene carbonate) by reacting 2,2,4,4-tetramethyl-1,3-cyclobutanediol, hereinafter referred to as "TMCD" for convenience, with the bis(ethyl carbonate) of TMCD in the presence of a dibutyltin oxide catalyst. However, this process only produces low molecular weight and discolored polymers having inherent viscosities below 0.4 dL/g.
Bis(phenyl carbonates) such as those used in U.S. Pat. No. 3,335,111 are known in the art as monomers for the production of polycarbonates. However, these aromatic monomers are expensive to produce and the phenol by-product ultimately imparts some undesirable color to the polymer.
In light of the above, it would be desirable to have a bis alkyl carbonate of TMCD and a method of making therefor that can be used in the production of high molecular weight poly(2,2,4,4-tetramethyl-1,3-cyclobutylene carbonate).